Multi-speed brush control

Abstract

An improvement for floor maintenance equipment employing electrically driven scrubbing or polishing brushes including means for varying the speed of the brush motors. Two brush speeds are provided by switching apparatus which change the interconnection of the brush motors from series to parallel and from parallel to series. This results in a substantial change in motor speed and power.

What we claim is: 
     
       1. Floor maintenance equipment including a plurality of rotary means for maintaining floor surfaces, said rotary means being driven by at least a pair of electric motors and means for varying the speed of said, electric motors, said speed varying means including electric circuitry for switching the voltage level applied to said electric motor means by selectively changing the electrical relationship between said motors from series to parallel and from parallel to series. 
     
     
       2. The equipment of claim 1 wherein said motors comprise at least two DC motors. 
     
     
       3. Floor maintenance equipment comprising a body, a plurality of wheels for supporting said body, power means for driving said wheels, means for steering said equipment, at least one pair of rotating brushes for acting on a floor surface, at least one pair of electric motors for driving said brushes, power means for supplying electric current to said motors, and circuit means for connecting said motors to said power means selectively in parallel or in series for varying the speed of said motors. 
     
     
       4. The equipment of claim 3 wherein said circuit means include switching means for changing the voltage applied to said motor means. 
     
     
       5. The equipment of claim 4 wherein said switching means includes a plurality of relays. 
     
     
       6. The equipment of claim 5 wherein said relays include a first and second pair of relays and wherein said power means includes a first and second power means. 
     
     
       7. The equipment of claim 6 wherein said switching means includes a switch having a first and second position, said first position operating said first pair of relays which connect said motors in parallel with each other, said second position operating said second pair of relays which connect said motors in series with each other. 
     
     
       8. Floor maintenance equipment comprising a body, a plurality of wheels for supporting said body, means for steering said equipment, first and second rotary cleaning and maintaining means for maintaining floor surfaces, first and second motor means for powering said first and second cleaning means respectively, drive means for driving said wheels, first and second electrical power sources, and switching means for connecting said first and second motor means to said first and second power sources selectively in series or in parallel. 
     
     
       9. The equipment of claim 8 wherein said switching means includes a switch having a first and second position, a first pair of relays operated by said switch in said first position, a first circuit which connects said first and second motor means in parallel with each other and in series with the series combination of said first and said second power source, said first pair of relays serving to activate said first circuit, a second pair of relays operated by said switch in said second position, a second circuit which connects said first motor means to said first power source and a third circuit which connects said second motor means to said second power source and wherein said second and third circuits include common conductor means which is shared by both said second and third circuits, said second pair of relays serving to activate said second and third circuits. 
     
     
       10. The equipment of claim 9 wherein said first pair of relays includes first and second relay contacts which connect said first and second motor means in series with said series combination of said first and second power sources and wherein said second pair of relays includes third and fourth relay contacts which connect said second and third circuits respectively. 
     
     
       11. Floor maintenance equipment including a plurality of rotary means for maintaining floor surfaces, said rotary means being driven by electric motor means including at least two DC motors, and means for varying the speed of said rotary means, said speed varying means including means adapted to selectively change the circuit operating said motors from series to parallel and from parallel to series. 
     
     
       12. Floor maintenance equipment comprising a body, a plurality of wheels for supporting said body, power means for driving said wheels, means for steering said equipment, first and second rotary cleaning means for maintaining floor surfaces, first and second motor means for powering said first and second cleaning means respectively, first and second power sources, said first and second power motor means being electrically connected to said first and second power sources, switching means for interconnecting said first and second motor means and said first and second power sources selectively in parallel or in series, said switching means including a switch having a first and second position, a first pair of relays operated by said switch in said first position, a first circuit which connects said first and second motor means while in parallel with each other to the series combination of said first and second power source, said first pair of relays serving to activate and deactivate said first circuit, a second pair of relays operated by said switch in said second position, a second circuit which connects said first motor means to said first power source and a third circuit which connects said second motor means to said second power source and wherein said second and third circuits include common conductor means which are shared by both said second and third circuits, said second pair of relays serving to activate and deactivate said second and third circuits. 
     
     
       13. Floor maintenance equipment including a plurality of rotary means for maintaining floor surfaces, said rotary means being operatively driven by at least two electric motors, and means for varying the speed of said rotary means, said speed varying means including switching means adapted for selectively changing the electrical relationship between said motors from series to parallel and from parallel to series. 
     
     
       14. Floor maintenance equipment comprising a body, a plurality of wheels for supporting said body, drive means for driving said wheels, means for steering said equipment, first and second rotary means for maintaining floor surfaces, first and second motor means powering said first and second rotary means respectively, first and second electrical power sources, and switching means for connecting said first and second motor means between a first electrical configuration connecting said motor means in series with each other and a second electrical configuration connecting said motor means in parallel with each other, so that said rotary means may be selectively operated at different speeds and power levels.